The proposed research is a continuation of our studies which is centered around the immunological reactivity of patients (with lung tumors, osteosarcomas) against their own tumor cells. We use mainly two assays: ATS-"autologous tumor stimulation" - blastogenesis of lymphocytes exposed to biopsy cells and ALC-"autologous lymphocyte cytotoxicity" exerted towards biopsy cells. The relevance of the outcome of these assays for the clinical situation will be looked for in retrospective analysis of the history of patients on which the tests were performed. T-cell lines with cytotoxic potential against autologous and allogeneic cells and against K562 will be tested for the question whether the reactivities are performed by the same or by different sets of lymphocyte present concomitantly in the cultures. We are introducing another autologous in vitro system, the "autologous mixed" culture (AMC) in which T lymphocytes are stimulated for proliferation by exposure to B cells and monocytes, Such cultures will be tested for generation of auto-tumor cytotoxicity. T cell lines will be grown from AMC and ATS systems with the help of TCGF. The proportion of precursor cells in the blood and in the tumor infiltrating lymphocyte population which respond with proliferation when exposed to autologous tumor cells, B cells or monocytes and allogeneic tumor cells will be compared. The parallel studies of auto-tumor and auto-B monocyte stimulatory system will help to ascertain the tumor specific nature of the lymphocyte reactivities.